Papers by Wolfram Adlassnig
Carnivorous plants trap and utilize animals in order to improve their supply with mineral nutrien... more Carnivorous plants trap and utilize animals in order to improve their supply with mineral nutrients. One strategy for prey capture is the use of adhesive traps, i.e., leaves that produce sticky substances. Sticky shoots are widespread in the plant kingdom and serve to protect the plant, especially flowers and seeds. In some taxa, mechanisms have been developed to absorb nutrients from the decaying carcasses of animals killed by the glue. In carnivorous plants sensu stricto, additional digestive enzymes are secreted into the glue to accelerate degradation of prey organisms. The glues are secreted by glands that are remarkably uniform throughout all taxa producing adhesive traps. They follow the general scheme of plant glandular organs: the glands consist of a stalk, a neck equipped with a suberin layer that separates the gland from the rest of the plant, and the glandular cells producing sticky secretions. This glue always forms droplets at the tip of the glandular hairs. In most genera, these glands produce only glue whereas enzymes for prey digestion are secreted by a second type of gland. Two types of glue can be distinguished, polysaccharide mucilage in Droseraceae, Lentibulariaceae and their relatives, and terpenoid resins in Roridulaceae. On the ultrastructural level, mucilage is produced by the Golgi apparatus. Resins can be expected to be produced by the endoplasmic reticulum and by leucoplasts. Adhesive traps are suitable not only for the capture of small animals but also for the collection of organic particles like pollen grains. The glue may contain toxic compounds but the prey usually dies from suffocation by clogging of its tracheae. In Pinguicula and Drosera, the performance of the traps is improved by a slow movement, i.e., the folding of the leaf around the prey animal upon stimulation. In some species of Nepenthes, a pitcher with smooth walls is filled with a sticky digestive fluid. Some organisms, however, have developed strategies to survive on the deadly traps. Several species of Hemiptera are able to walk on the sticky traps and nourish on the prey; their faeces are absorbed by the plant. In Roridula, this relationship is highly specialized and essential for both the plant and the insect. Mutualistic fungi and bacteria are common in many adhesive traps where they degrade and dissolve the plant’s prey. The traps of Drosera, on the other hand, are virtually sterile. In spite of the extensive literature on adhesive traps, numerous questions still remain. Only a small percentage of “sticky” plants have actually been tested for carnivory. The properties and composition of their glues are widely unknown. In advanced adhesive traps, the mechanisms regulating secretion and absorption are poorly understood. Thereby, some glues may be applicable for human as they are non-toxic, quite stable under environmental conditions, and partly exhibit mildly antibiotic properties. Some carnivorous plants with adhesive traps have been used by humans for the capture of insects as well as for food processing.
Carnivorous plants may benefit from animal-derived nutrients to supplement minerals from the soil... more Carnivorous plants may benefit from animal-derived nutrients to supplement minerals from the soil. Therefore, the role and importance of their roots is a matter of debate. Aquatic carnivorous species lack roots completely, and many hygrophytic and epiphytic carnivorous species only have a weakly developed root system. In xerophytes, however, large, extended and/or deep-reaching roots and sub-soil shoots develop. Roots develop also in carnivorous plants in other habitats that are hostile, due to flooding, salinity or heavy metal occurance. Information about the structure and functioning of roots of carnivorous plants is limited, but this knowledge is essential for a sound understanding of the plants’ physiology and ecology. Here we compile and summarise available information on: The morphology of the roots. The root functions that are taken over by stems and leaves in species without roots or with poorly developed root systems; anchoring and storage occur by specialized chlorophyll-less stems; water and nutrients are taken up by the trap leaves. The contribution of the roots to the nutrient supply of the plants; this varies considerably amongst the few investigated species. We compare nutrient uptake by the roots with the acquisition of nutrients via the traps. The ability of the roots of some carnivorous species to tolerate stressful conditions in their habitats; e.g., lack of oxygen, saline conditions, heavy metals in the soil, heat during bushfires, drought, and flooding.kg]Key words
Applied Radiation and Isotopes, 2009
Carnivorous plants use animals as fertiliser substitutes which allow them to survive on nutrient ... more Carnivorous plants use animals as fertiliser substitutes which allow them to survive on nutrient deficient soils. Most research concentrated on the uptake of the prey's nitrogen and phosphorus; only little is known on the utilisation of other elements. We studied the uptake of three essential nutrients, potassium, iron and manganese, in three species of carnivorous pitcher plants (Cephalotus follicularis LaBilladiere, Sarracenia purpurea L., Heliamphora nutans Bentham). Using relatively short-lived and g-emitting radiotracers, we significantly improved the sensitivity compared to conventional protocols and gained the following results.
Plant Ecology, 2008
Aquatic carnivorous plants of the genus Utricularia capture and utilise a wide range of small aqu... more Aquatic carnivorous plants of the genus Utricularia capture and utilise a wide range of small aquatic organisms. Most of the literature focuses on animals as prey. In this study, we investigate the occurrence of algae inside the traps of four species of bladderwort. We observed that algae of 45 genera form up to 80% of the total prey; algae were found frequently in traps without animal prey. The majority are coccal and trichal algae of the families Desmidiaceae and Zygnemataceae. The percentage of algae increases significantly with decreasing electric conductivity of the water (r S = −0.417; P = 0,000). Thus, algae are the most frequent prey in extremely soft waters. The percentage of algae did not differ significantly, not within the investigated Utricularia species or within the various study sites. However, the taxonomic composition of the algal prey showed highly significant differences between different sites. More than 90% of the trapped algae were killed and degraded by the bladders. The recent data allow for two alternative hypotheses: either algal prey supplements animal prey in oligotrophic waters, or the unprofitable trapping of algae is rather an additional stress factor for Utricularia and contributes to its limited distribution in some peat bogs.
Ecological Research, 2006
The carnivorous plant Drosophyllum lusitanicum inhabits heathland and ruderal sites in Portugal, ... more The carnivorous plant Drosophyllum lusitanicum inhabits heathland and ruderal sites in Portugal, Spain and Morocco. In the literature, various theories have been discussed concerning the ability of Drosophyllum to survive the annual dry period in summer. In August 2004, we examined: (1) the microclimate, (2) soil parameters and (3) the physiological conditions of the plants on two sites in Portugal and Spain. First, during the day, plants are exposed to very high air and soil temperatures and very low air humidity. The climatic extremes are not significantly softened by the population, only the wind speed is drastically decreased. During the night, on the other hand, very high air humidity and dew formation could be observed. The harsh climate is accompanied by stressful soil conditions. Second, the soil is completely dry, poor in fine earth, calcium and nutrients and more or less acid. Third, in spite of these climatic and edaphic extremes, all plants were green, produced trapping mucilage and caught numerous animals. Far from being affected by these conditions, Drosophyllum showed even better growth and reproduction on more extreme sites. We analysed the root system and found living fine roots missing. The osmotic value of the plants is rather low and water storage organs are absent. Therefore we conclude that in summer Drosophyllum is nourished by the dew at night.
Brazilian Archives of Biology and Technology, 2010
The aim of this study was the study of the abiotic environment of the carnivorous pitcher plant H... more The aim of this study was the study of the abiotic environment of the carnivorous pitcher plant Heliamphora nutans (Sarraceniaceae), including the microclimate and the geochemistry of the soil of the growing sites on Roraima Tepui and discuss their relevance within the recent model of carnivorous plant ecology. The soil was peaty and low in nutrients. The microclimate on the site was very balanced, with moderately cool temperatures, a constant high humidity and very low wind speed. Heliamphora was not exposed to any recognizable climatic stress. Previous macroclimatic measurements reflected the growth conditions of Heliamphora only incorrectly, since humidity decreased drastically with height. The apparent conflict with the common model of carnivorous plant ecology was caused by the dense surrounding vegetation. However, the leaf coverage of these non carnivorous plants was too low to cause significant insolation decrease for Heliamphora. Furthermore, the temperature regime of the pitcher fluid was more balanced than the temperature of the leaf. This may improve conditions for the growth of microorganisms in the pitcher fluid that contribute to the degredation of the plant's prey.
Plant and Soil, 2005
Carnivorous plants may benefit from animal-derived nutrients to supplement minerals from the soil... more Carnivorous plants may benefit from animal-derived nutrients to supplement minerals from the soil. Therefore, the role and importance of their roots is a matter of debate. Aquatic carnivorous species lack roots completely, and many hygrophytic and epiphytic carnivorous species only have a weakly devel-oped root system. In xerophytes, however, large, extended and/or deep-reaching roots and sub-soil shoots develop. Roots develop also in carnivorous plants in other habitats that are hostile, due to flood-ing, salinity or heavy metal occurance. Information about the structure and functioning of roots of car- nivorous plants is limited, but this knowledge is essential for a sound understanding of the plants’ physiology and ecology. Here we compile and summarise available information on: (1) The morphology of the roots. (2) The root functions that are taken over by stems and leaves in species without roots or with poorly developed root systems; anchoring and storage occur by specialized chlorophyll-less stems; water and nutrients are taken up by the trap leaves. (3) The contribution of the roots to the nutrient supply of the plants; this varies considerably amongst the few investigated species. We compare nutrient uptake by the roots with the acquisition of nutri-ents via the traps. (4) The ability of the roots of some carnivorous species to tolerate stressful conditions in their habitats; e.g., lack of oxygen, saline conditions, heavy metals in the soil, heat during bushfires, drought, and flooding
Open Environmental Sciences, 2009
This paper is on the biological impact of arsenic and antimony on the flora and microflora on a f... more This paper is on the biological impact of arsenic and antimony on the flora and microflora on a former Sbmining site in Schlaining (Stadtschlaining, Burgenland, Austria). Several habitats were investigated with respect to biodiversity and metalloid contamination in soil. Although the overburden of the mining activity had been remediated less than ten years ago, metalloid concentrations occurred in soil up to 1.4‰ As and 3.6% Sb, respectively, in some microhabitats, as determined by Instrumental Neutron Activation Analysis. These metalloids were embedded into a nonuniform mineralogical background. Metalloid mobility could not be explained by common models, indicating that predictions on the mobility of geogenic metalloids require additional mineralogical data. The biological effects of this contamination were variable. We observed that metalloid resistant strands of microorganisms appeared in the contaminated soil. In cultivation experiments, Sb was found to be more toxic than As. Sulphur oxidising strand were more resistant than organotrophic ones and grew even better on cultivation media spiked with 10 ppm As than on the unspiked control. The flora was only partially influenced: the lowest biodiversity was found in metalloid richest soils, but moderate contamination resulted in enhanced species numbers. Only in one case, where the pH-buffering capacity of the soil was exceeded by consumption of the entire carbonate, no embryophytes occurred. This was probably due to extreme pH conditions as well as to metalloid concentrations. Our data support the hypothesis that higher plants are rather affected by extreme soil conditions, which often coincide with As contaminations, than by the contamination itself. A small rivulet in this area contained 26 g/l and thus exceeded the WHO guideline value for As in drinking water by a factor of 2.6. Indeed we observed a diminished biodiversity in this rivulet. § Wolfram Adlassnig and Georg Steinhauser contributed equally to this work. mine. In the late 1990s, the ore has been depleted and consequently, the mine had to be abandoned in 1999. For more information on socioeconomic aspects of antimony mining in Stadtschlaining, compare Halisch [2].
Plant Biology, 2006
Abstract: A new ELF (enzyme labelled fluorescence) assay was applied to detect phosphatase activi... more Abstract: A new ELF (enzyme labelled fluorescence) assay was applied to detect phosphatase activity in glandular structures of 47 carnivorous plant species, especially Lentibulariaceae, in order to understand their digestive activities. We address the following questions: (1) Are phosphatases produced by the plants and/or by inhabitants of the traps? (2) Which type of hairs/glands is involved in the production of phosphatases? (3) Is this phosphatase production a common feature among carnivorous plants or is it restricted to evolutionarily advanced species? Our results showed activity of the phosphatases in glandular structures of the majority of the plants tested, both from the greenhouse and from sterile culture. In addition, extracellular phosphatases can also be produced by trap inhabitants. In Utricularia, activity of phosphatase was detected in internal glands of 27 species from both primitive and advanced sections and different ecological groups. Further positive reactions were found in Genlisea, Pinguicula, Aldrovanda, Dionaea, Drosera, Drosophyllum, Nepenthes, and Cephalotus. In Utricularia and Genlisea, enzymatic secretion was independent of stimulation by prey. Byblis and Roridula are usually considered as “proto-carnivores”, lacking digestive enzymes. However, we found high activity of phosphatases in both species. Thus, they should be classified as true carnivores. We suggest that the inflorescence of Byblis and some Pinguicula species might also be an additional “carnivorous organ”, which can trap a prey, digest it, and finally absorb available nutrients.
Plant Journal, 2011
A major question in pollen tube growth in planta remains: do the pollen tube walls form a barrier... more A major question in pollen tube growth in planta remains: do the pollen tube walls form a barrier to interaction with the environment? Using cryo-FESEM, we directly assessed the 3D construction and porosity of tobacco pollen tube walls. Fractured mature primary walls showed a 40-50 nm spaced lattice of continuous fibers interconnected by short rods in the primary wall. These observations agree with TEM observations of sectioned walls. In the secondary callose wall, for which no structure is visible using TEM, cryo-FESEM also revealed a 50 nm lattice consisting of longer fibers, approximately 10-15 nm wide, with rod-like, thinner interconnections at angles of approximately 90°with the longer fibers. Such architecture may reflect functional needs with respect to porosity and mechanical strength. The wall does not form a mechanical barrier to interaction with the environment and is gained at low cost. Cryo-FESEM additionally revealed another special feature of the wall: the tubes were tiled with scales or rings that were highly conspicuous after pectin extraction with EDTA. These rings cause the typical banding patterns of pectin that are commonly seen in pollen tubes during oscillatory growth, as confirmed by staining with toluidine blue as well as by DIC microscopy. Growth analysis by VEC-LM showed that the ring-or scale-like structures of the primary wall consist of material deposited prior to the growth pulses. The alternating band pattern seen in the callose wall is probably imposed by constrictions resulting from the rings of the primary wall.
Uploads
Papers by Wolfram Adlassnig